Conceptually, Dexim's P-Flip Power Play Dock ($55) is a neat product. Like numerous other companies, Dexim has taken a battery -- supposedly a 2000mAh one -- and wrapped it in a shell that cleanly provides three bright blue power LEDs, a mini-USB recharging port, and a power button for your use. The twist: a rotating plastic iPod touch, iPhone 3G and 3GS dock that folds down for storage or out to keep your iPhone standing upright; you can turn it on its side and use it as a video stand, as well. It's bundled with a USB cable so you can recharge it from your computer. Five colors are available, all plastic with metallic-ish finishes.

But there are a few issues with P-Flip that keep it from being worthy of our recommendation. Put aside the lengthy recharging time, which seemed to take abnormally long—6 or so hours—to replenish the depleted cell. There’s the oddity of the battery life, which despite its 2000mAh rating somehow failed to completely refill the battery of a fully emptied iPhone 3G, which has only a 1300mAh battery inside: instead of a full charge and a half, as would be expected, P-Flip only brought it back to the 75% charged point.

Even if we blamed this on an inefficiency that wastes extra power when the iPhone is completely discharged, the life of the P-Flip battery still wouldn’t be quite where we expected it to be. Our impression after a couple of tests is that the battery performs in the 1500mAh range or lower; whether this is due to electrical issues or something in our review sample, we’re not sure.

Another issue is the dock design. On the plus side, P-Flip can serve as a computer synchronization dock in addition to working as a stand, and for portability junkies, the clean upright docking plus battery combo solution may make a lot of sense. The iPhone’s bottom speaker isn’t blocked by the dock, so audio is just as audible when it’s inside P-Flip as when it’s outside.

On the other hand, P-Flip does block the iPod touch’s headphone port—a bigger problem for speaker-less iPod touch 1G users than in its sequels—and it doesn’t provide a great viewing angle or much device edge protection when turned on its side. Since widescreen video viewing is one of the most battery-draining features of Apple’s devices, those expecting to use the accessory for this purpose may well be disappointed. It only feels right when used with applications that can be accessed from the iPod touch or iPhone in an upright position, on a flat surface.

All of this isn’t to say that P-Flip is a bad accessory. It’s not. But between its underwhelming battery and the design of its dock, which will appeal only to certain types of iPod touch and iPhone users—frankly, not us given the way we use batteries with our devices—it could use a little rethinking and improvement. The concept is a good one, but the execution could stand to be a bunch better.

Updated March 26, 2010: Dexim provided a replacement sample for the original P-Flip we tested, identical to the first physically except for the new inclusion of a clear plastic and foam padded second insert that can be used to resize the dock for an unencased iPod touch. We agreed to give it another shot to see whether our first unit was bad, given that Dexim insisted—and we believed—that the battery should be capable of 2000mAh output. Across several separate tests, the situation with this P-Flip unit became clear: recharging of its battery was very slow, as we had noticed before, but under the right conditions, it came much closer to the 2000mAh mark than the other unit, fully recharging an iPhone or an iPod touch with enough spare juice at the end to roughly half-charge the same device. Under the wrong conditions—leaving the P-Flip connected to, say, an iPhone 3GS for a period of time after the charging was complete, we noticed that P-Flip didn’t automatically turn itself off, and continued to trickle-recharge the connected device until the battery was more substantially drained. We leave our rating of P-Flip intact, but still feel that this is a neat enough accessory that’s on the slow side for recharging, and would benefit from a little tweaking for a future update.

Editors' Note: iLounge only reviews products in "final" form, but many companies now change their offerings - sometimes several times - after our reviews have been published.
This iLounge article provides more information on this practice, known as revving.